Self-adjusting lock



May 5, 1970 v. o. SMITH ETAL SELF-ADJUSTING LOCK 2 Sheets-Sheet 1 Filed DSC. 14, 1967 INVENTORS Vf/e/VO/V 0 5/7/77/ May 5,` 1970 v. o. `s-Mrn-l ETAL SELF-ADJUSTING LOCK 2 Sheets-$heet 2 Filed Dec. 14, 1967 INVENTORS Vele/V0# 0. srl/7W United States Patent O U.S. Cl. 292-241 11 Claims ABSTRACT F THE DISCLOSURE A lock structure for an upwardly acting door of a truck van wherein a latch bolt and a manually engageable actuating member are pivotally mounted upon the door Ifor movement around an axis substantially perpendicular to the plane of the door when it is in the closed position. The latch bolt has an elongated, arcuate hook portion adapted to extend below the lower edge of the door for engagement with a roller mounted in the truck bed. First resilient means urges the latch bolt to move with respect to the actuating member into the locking position, and second resilient means urges the actuating member away from a selected position holding the latch bolt in the locking position. Keeper means releasably holds the actuating member in said selected position.

BACKGROUND OF THE INVENTION This invention relates in general to a lock structure for an upwardly acting truck door and, more specifically, to a type thereof which is capable of automatic, self adjustment to compensate for looseness in the door incident to wear or the tolerances of a conventional installation and which is incapable of accidental opening. Persons familiar with the manufacture and maintenance of upwardly acting doors for truck vans, for example, have long been aware that the lock structures in such doors are subject to unusually rough treatment, even under substantially normal operating conditions. That is, truck doors and their lock structures are constantly exposed to the weather, they are often ybattered and strained by the loads carried in the truck van and they are frequently subjected to excessive forces when the truck (or other vehicle) upon which they are mounted moves over uneven terrain. As a result, any looseness in the latching mechanism of the lock, which may be produced by normal wear, by improper initial installation or by lack of adjustment, is quickly magnified and accelerated into excessive and abnormal wear or even complete failure. Where the looseness occurs between the latch bolt on the door and the catch in the truck bed, the result is a dancing door which is not only noisy and unsightly, but also aggravates the wear problem and usually accelerates lock failure. Moreover, because of the looseness in the latching mechanism, the door will tend to vibrate even when the vehicle is moved along substantially level terrain.

Many attempts have been made to avoid, or at least minimize, loose doors or loose door latching mechanisms on trucks, and a lock structure designed for this purpose is disclosed in my patent application Ser. No. 669,481, led Sept. 21, 1967 and entitled Truck Door Lock. Other structures for this purpose are described in the aforesaid application.

However, while the latch mechanism in `my aforesaid application does greatly reduce the aggravated wear encountered by other types of latch mechanisms, where some looseness exists in the door, said latch mechanism does not eliminate the door movement. In fact, it is expressly designed so that the door can move somewhat. However, such movement is resisted and excessive wear ice or damage to the latch mechanism is avoided by resiliently flexible means associated with the catch.

There are-many circumstances where it is desirable to eliminate virtually all movement of the truck door When its lock is in the latched position. However, since it is at least economically impractical to construct a truck van and/ or truck door of the upwardly acting type having no play, at least some looseness is present in the door when it is latched. Accordingly, the next best solution is to provide a latch mechanism which automatically adjusts itself to absorb or counteract any looseness which exists or subsequently develops in the door latch, as the result of movement of the vehicle or the door, while the door is in the latched position.

Accordingly, a primary object of this invention is the provision of an improved lock structure for an upwardly acting truck door wherein the latch mechanism of the lock structure is adapted to adjust automatically for, and thereby eliminate, looseness between the door and the truck bed resulting from normal Wear, minor inaccuracies of installation, acceptable tolerances in parts and the relative movements of the various parts olf a truck van associated with the door during normal operation of the truck, rwhereby the useful life of the lock structure and/or the door is extended.

=A further object of this invention is the provision of a lock structure, as aforesaid, in which the one-piece latch bolt has an elongated hook portion with a cammed surface which slideably engages the catch means in the truck bed by a relatively gradual wedging action, and in which the hook portion is continuously and resiliently urged toward the locking position with said catch means when the lock mechanism is in its latched position.

A further object of the invention is the provision of a lock structure, as aforesaid, wherein the catch means includes antifriction means engageable with the hook portion of the latch bolt to minimize frictional losses in eecting engagement and disengagement between the latch bolt and the catch means.

A further object of this invention is the provision of a lock. structure, as aforesaid, which can be readily installed by a person capable of installing existing lock structures for the same or similar purposes, which can be easily operated by any person capable of operating the truck upon which the lock structure is installed and which requires a minimum of adjustment when the lock structure is installed or during its subsequent use in order to overcome normal looseness which normally develops in upwardly acting truck doors.

Other objects and purposes of the invention will become apparent to persons familiar with lock structures for truck doors upon reading the following descriptive material and examining the accompanying drawings, in which:

FIG. l is a broken, fragmentary rear elevational view of a truck door and an adjacent portion of a truck bed including the lock structure embodying the invention.

FIG. `2 is a sectional view taken along the line II-II in FIG. l.

FIG. 3 is a sectional view taken along the line III- III in FIG. 2.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1.

FIG. 5 is a sectional view taken along the line V- in FIG. 1.

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5.

FIG. 7 is a sectional view substantially as taken along the line VII-VII in FIG. 1.

FIG. 8 is a sectional view taken along the line VIII- VIII in FIG. 2.

FIG. 9 is a rear elevational view of said truck door showing the lock structure in its unlatched position.

FIG. 1() is a sectional view taken along the line X-X in FIG. 9.

For convenience in description, the terms upper, lower, left, right, front, rear and words of similar import will have reference to the locking structure of the invention and the parts of the tru-ck door associated therewith as appearing in FIG. 1 which discloses the rear side of the lock structure. The terms innen outer and derivatives thereof will have reference to the lock structure of the invention and parts associated therewith.

SUMMARY OF THE INVENTION The objects and purposes of the invention, including those set forth abo-ve, have been met by providing a lock structure comprising an antifriction catch means mounted in the bed of a truck or similar vehicle and a latch mechanism mounted upon an upwardly acting door of the truck van and having a latch bolt including an elongated hook portion with a cammed inner surface engageable with the catch. The latch bolt is pivotally mounted upon the door and resiliently urged into the locking position by an actuating member which is held in the locked position by primary and secondary keepers. Resiliently exifble means connected between the actuating member and the door urges the actuating member, hence the latch bolt, away from the locking position.

DETAILED DESCRIPTION The lock structure of the invention, a preferred` embodiment of which is disclosed in FIGS. l and 2, is cornprised of a latch assembly 11, which is mounted upon the lower end of an upwardly acting door 12, for engagement with a catch assembly 13 which is mounted in the bed 14 of an otherwise substantially conventional truck van, of which the door 12 is a part. In this particular embodiment, the door 12 is comprised of a plurality of horizontally hinged sections 16 which are disposed in a substantially vertical plane when the door is closed and in a substantially horizontal plane near the roof of the van when the door is open. A resiliently flexible weather seal (FIG. 2) is mounted upon the lower edge of the door 12 and is engageable with the bed 14 in a conventional manner and for conventional purposes.

The catch assembly 13 (FIGS. 1, 2 `and 3) is comprised of an elongated, substantially rectangular casing 17 which is preferably fabricated from sheet steel to form a top plate 18, a pair of sidewalls 19 and 21 and a pair of end walls, such as wall 22. The sidewalls 19 and 21 and the end walls 22 define a catch chamber 23 having an upwardly facing opening 24. The opening 24 provides an access for the latch bolt 47 and the chamber 23 opens downwardly for drainage.

The top plate 18 (FIG. 2) preferably extends beyond both end walls 22 and the rear sidewall 21 for engagement with the upper surface 26 of the bed 14 when the casing 17 is located within the opening 27 in the bed 14. The top plate 18 may be secured to the bed 4 by Welding, by screws or any other convenient, conventional means.

The catch assembly 13 includes a sleeve 28 which is rotatably supported on a catch pin 29, which is secured to and extends between the sidewalls 19 and 21 of the casing 17 about midway between the end walls 22.

The latch assembly 11 (FIG. 1) has a mounting plate 31 which is secured to the rear surface of the door 12 adjacent the lower edge thereof by means of rivets 32. Axle has a threaded portion 40 of reduced diameter which extends through an opening in the mounting plate 31 and which engaged by a nut 41 which secures said axle 42 to plate 31. An actuating member or latch support member 33 (FIGS. l, 2 and 3) which is rotatably supported on axle 35, is compn'sed of an elongated housing 34 having a front wall 36 and a partial rear wall 37 interconnected by a peripheral wall 38 having a substantial opening 39 (FIG. 8) along the lower side thereof. The front wall 36 (FIG. 2) of housing 34 has an integral hub 42 through which the axle 35 extends to pivotally support the actuating member 33. The wall 37 of the housing 34 also has an opening 45 through which an axle 35 is rotatably received. A

The actuating member 33 (FIG. 1) has an integral arm or handle 43 which projects from the housing 34 lengthwise thereof and substantially radially of the axle 35. A pin 44 (FIGS. 3, 5 and 6) extends rearwardly from the mounting plate 31 and is secured thereto, as by Welding. The arm 43 has a stop ange 46 (FIG. 3) which engages pin 44 and thereby limits the counterclockwise (FIG. 3) or latching movement of the handle 43.

The latch bolt 47 (FIG. 3) has a shank 48, which is rotatably supported at its upper end upon the axle 35, and an elongated, arcuate hook 49 integral with the lower end of the shank 48 and having a slightly cammed inner surface 51. The portion of Surface 51 adjacent shank 48 is nearer to axle 35 than is the portion of surface 51 adjacent the free end of the hook 49. The spiral spring 52 is held `between the front wall 36 and a retainer 53. One end of the spirial spring 52 bears against the shank 4S of latch bolt 47 and the other end thereof bears against the peripheral wall 38 of housing 34, whereby the tension of said spring urges the latch bolt 47 (FIG. 8) in a counterclockwise or latching direction, such urging being limited by the engagement of the shank 48 with the edge of the periperal wall 38 defining the edge 54 of the opening 39.

A coil spring 56 (FIGS. 2 and 3), which encircles the axle 35, has a hook 57 at its outer end, which is engaged with the front wall 36 of the housing 34, and a hook 58 on its inner end which is received through a slot 59 in the mounting plate 31. The coil spring 56 is under tension whereby it urges the actuating member 33 in a clockwise or unlatching direction, as appearing in FIG. 3, toward a position in which the peripheral wall 38 engages a pin 62 (FIG. 9) which extends from wall 31. The peripheral wall 38 may extend forwardly, as shown in FIG. 2, somewhat beyond the front wall 36 of the housing 34 to provide a weather shield for the coil spring 56.

The primary keeper or pawl 63 (FIGS. 3, 5 and 6) is pivotally mounted upon a pivot pin 64 which is rigidly secured to the handle 43 near the housing 34. The primary keeper 63 has a cam surface 67 and a locking surface 68 substantially transverse of the surface 67. A spiral spring 69, which encircles the pivot pin 64, has a hook 71 which is engaged with an edge of the rearwardly extending flange 72 on arm 43. The other end 74 of Coil spring 69 is engaged with flange '73, which extends along and defines part of the cam surface 67 of primary keeper 63. The spiral spring 69 is under constant tension urging the surface 67 of primary keeper 63 toward contact with the peripheral wall 38 of housing 34.

The thumbgrip 66 (FIG. 6) is integral with and projects upwardly from the primary keeper 63 for manually moving same against the contrary urging of the spring 69 and away from contact with the peripheral Wall 38, after which the actuating member 33 can be rotated in a clockwise direction (FIG. 3), thereby disengaging latch bolt 47 from the catch assembly 13. The carn surface 67 is so positioned that clockwise movement of the actuating member 33 from its FIG. 9 position to its FIG. 6 position will automatically cause said surface 67 to engage pin 44 and rotate primary keeper 63 in a clockwise direction until the surface 68 can slide under the pin 44. The spiral spring 69 holds the pin 44 locked between the surface 68 of keeper 63 and the stop flange 46.

The secondary keeper or pawl '79 (FIGS. l and 4) is substantially flat and has an integral hub 81 near one edge thereof which is sleeved upon the pivot pin 82. The pivot pin 82 is rigidly secured to a' support plate 83 which iS riveted to the door 12 so that the pivot pin 82 is preferably (but not necessarily) located at a point from the axle 35 slightly greater than the distance between said axle and the outer end of the arm 43. The arm 43 has a downward and frontward projection 84 which is located at the outer end of the arm 43 and is adjacent the lug 86 on the keeper 79 when said keeper is suspended freely from the pivot pin 82. The projection 84 has an opening 87 (FIG. 4) which is aligned with an opening 88 in lug 86 when the latch assembly 11 is in its latched position of FIG. 1.

The keeper 79 has an arcuate edge 91 (FIG. 3) which extends over and is engageable by the upper edge 92 of the projection 84 when the keeper 79 is in its normal depending position. Accordingly, if the primary keeper 63 should be accidentally disengaged from the pin 64, due to irregular movements of the truck, for example, the arcuate edge 91 in the path of the projection 84 will positively prevent the actuating member 33 from rotating in a clockwise direction under the urging of the coil spring 56.

An integral flange 93 (FIG. 7) is provided on the support plate 83 rightwardly of the pivot pin 82 for engagement by the lug 86 for retaining the keeper '79 in an inoperative position with respect to the movement of the actuating member 33 and its arm 43. The keeper 79 is moved into the inoperative position by rotating the actuating member 33 into its unlocked position shown in FIG. 9, after which the lug 86 is manually grasped and the keeper 79 is rotated in a clockwise direction until lug 86 engages and rests upon the upper surface of the flange 93.

When the secondary keeper 79 is in its normal position of operation (FIG. 1) obstructing upward movement of the arm 43, it can be manually pivoted in a counterclockwise direction around the pin 82 so that edge 91 is not above the projection 84. However, when the arm 43 is returned from its disengaged position of FIG. 9 to its latched position of FIG. 1, the projection 84 strikes the upper edge 92 of the keeper 79 on the left-ward side of the pivot pin 82 and thereby pivots the keeper 79 in a counterclockwise direction until the projection 84 reaches a position below the arcuate edge 91 whereupon the keeper 79 will swing into its FIG. l position and thereby block upward movement of the projection 84, hence the arm 43.

The length and radius of the arcuate edge 91 are preferably selected so that the edge 91 cannot be moved away from a position obstructing the upward movement of the projection 84 when a conventional sealing band 94 is threaded through the aligned openings 87 and 88 in projection 84 and lug 86.

The mounting plate 31 has an integral, rigid and substantially horizontal stop or tab 96 which extends rearwardly from the door 12 beneath and adjacent the rightward end of the housing 34 when the latch assembly 11 is in its latched position. The housing 34 has an integral, downwardly projecting pin 97 which extends through a central opening 98 in stop 96, whereby both lateral and downward movement of the latch assembly 11 is positively limited when said latch assembly is in its latched position.

OPERATION The operation of the door lock structure described above will be apparent from such description to a person of ordinary skill in the manufacture of truck door locks. However, primarily for the purpose of convenience, the lock operation will now be summarized.

When it becomes desirable to engage the latch assembly 11, the handle 43 (FIG. 9) is roated in a clockwise direction until the hook 49 of the latch bolt 47 engages the sleeve 28 in the catch assembly 13. Since the upper surface 51 of hook 49 is cammed, the outer end thereof passes easily beneath the rotatable sleeve 28 until the surface 51 `firmly engages said sleeve 28. The latch assembly 11 and catch assembly 13 are preferably installed on the truck so that the sleeve 28 is snugly engaged by the midportion of the cammed surface 51 when the housing 34 is closely adjacent the stop 96, as shown in FIG. 1.

As the handle 43 is moved into the latched position of FIG. 1, engagement of the hook 49 by sleeve 28 effects a clockwise movement of the member 33 relative to bolt 47, thereby compressing spring 56. Thereafter, should the door 12 be jarred or shifted downwardly, as during operation of the truck, spring 52 forces the latch bolt 47 in a clockwise direction, thereby taking up any slack that may develop between surface 51 and sleeve 28.

As the latch assembly 11 moves into its latched position, the pin 97, which is preferably slightly arcuate around the axis of axle 35, is received through the opening 98 in stop 96. Thus, lateral movement of the handle 43 away from the door 12, which might be possible after the lock structure becomes worn or due to faulty assembly or parts, is positively prevented by the pin 97. Accordingly, the engagement of the pin 97 with the stop 96 also minimizes the rattling noise and further wear resulting from a loose handle 43. In fact, said pin and stop prevent an unauthorized, non-destructive release of the latch which could occur if the arm 43 becomes suficiently loose to bypass the pin 44 and the keeper 79 on the rearward sides thereof.

When it becomes desirable to disengage the latch bolt 47 from the catch assembly 13, the secondary keeper 79l (FIG. 1) is roated in a counterclockwise direction and the primary keeper 63 is pivoted in a clockwise direction whereby the handle 43 is urged upwardly and pivoted around the axle 3S by the springs 52 and 56 (FIG. 3). Continued unlatching rotation of the actuating member 33 causes the hook 49 of latch bolt y47 to move from beneath the sleeve 28. The unlatching rotation of member 33 ultimately is limited (FIG. 9) by the engagement of wall 3S with pin 62 when the member 33` reaches a substantially horizontal position where it will not interfere with opening or closing movement of the door.

If the hook 49 has become seized with the sleeve 28, such seizure can be easily released by manually and abruptly pivoting member 33 in a counterclockwise direction away from a position just above the latched position of FIG. 1. This action causes the edge 54 of peripheral wall 38 (FIG. 8) to strike with considerable mechanical advantage against the shank 48 of the bolt 47, whereby the hook 49 will be freed.

Although a particular preferred embodiment of the invention has been disclosed above for illustrative purposes, it will be understood that variations or modifications of such disclosure are fully contemplated.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

What is claimed is:

1. In an upwardly acting door for the van of a truck having a bed, a door lock structure, comprising:

an actuating member pivotally mounted upon the door near the lower edge thereof for movement around a rst axis parallel with said bed when said lower edge is adjacent thereto;

a latch bolt pivotally supported upon said door for movement around said axis and with respect to said actuating member, said latch bolt having elongated arcuate hook means adapted to extend below said lower edge of said door, the radially inner surface of said hook means near the free end thereof being spaced radially from said axis a distance slightly greater than the opposite end of said surface;

roller means mounted to said bed for movement around a second axis substantially parallel with and below said first axis for engagement by said surface of said hook means, whereby the lower edge of said door is held closely adjacent said bed;

keeper means having parts thereof mounted upon said door and said actuating member adapted to hold said actuating member in a selected position with respect to said door, wherein said hook means is held in a position beneath said roller means when said edge of said door is closely adjacent said bed;

rst resiliently flexible means supported by said actuating member and yieldably urging said hook means into engagement with said roller means when said edge of said door is closely adjacent said bed; and

second resiliently flexible means connected to said door and yieldably urging said actuating member away from said selected position, whereby said hook means is moved out of engagement with said roller means. 2. A lock structure according to claim 1, wherein: said actuating member has an elongated, manually engageable arm extending substantially radially away `from said rst axis, said arm having an abutment projecting therefrom toward said door; and

wherein said keeper means comprises said abutment and a pawl pivotally mounted upon said door for engagement by said abutment when said actuating member is in said selected position for positively and releasably preventing movement of said actuating member out of said selected position under the urg ing of said second resiliently ilexible means.

3. A lock structure according to claim 2, including:

second keeper 4means having a second pawl pivotally mounted upon said actuating member between said first axis and said abutment, and pin means secured to said door and engageable by said second pawl means for releasably and positively holding said actuating member in said selected position.

4. A structure according to claim 1, wherein said actuating member has flange means extending toward said door and engageable by said latch bolt as said actuating member is moved away from said selected position under the urging of said second resiliently flexible means, and said latch -bolt being yieldably held against said ange means by said first resiliently flexible means, said flange means being engaged with said latch bolt substantially before said actuating member is moved into a second position wherein said hook means lis out of a position beneath said roller means.

l5. A structure according to claim 1, including a mounting plate rigidly secured to said door and shaft means pivotally supporting said actuating member and said latch bolt, said shaft means being rigidly secured to said mounting plate; and

pin means rigidly secured to said mounting plate and engageable by said actuating member for positively limiting pivotal movement thereof beyond approximately 180 degrees from said selected position thereof.

y6. A structure according to claim 1, wherein said roller means comprises a catch pin rigidly secured to said bed -below said upper surface thereof and sleeve means rotatably mounted upon said catch pin, said inner surface of said hook means defining part of an involute curve.

7. A structure according to claim 1, including a resiliently exible sealing element secured along the said lower edge of said door, said sealing element being resiliently compressible against said bed, whereby relative movement between said door and said bed will tend to compress said sealing element and subsequently move said inner surface of said hook means in a latching direction along said roller means.

S. A lock structure according to claim 1, including stop means on said door adjacent a lower edge of said actuating member when said member is in said selected position, said stop means having a vertical opening; and

pin means on said actuating member snugly and slideably receivable into the op-ening in said stop means when said member is in said selected position.

9. A lock structure according to claim 4, wherein the side of said latch bolt engaged by said flange means extends substantially radially Ifrom said rst axis, whereby the direction of movement of said flange means at the moment of impact with said side of said latch bolt isv parallel with the tangent to said inner surface of said hook means at the point thereon in engagement with said roller means.

10. In an upwardly acting door for the van of a truck having a bed, a door lock struct-ure, comprising:

an actuating member pivotally mounted on the door near the lower edge thereof for movement about a rst axis parallel with said bed when said lower edge is adjacent thereto;

a latch bolt pivotally supported upon said door for movement about said axis and with respect to said actuating member, said latch bolt having elongated arcuate hook means adapted -to extend below said lower edge of said door, the radially inner surface of said hook means near the free end thereof being spaced radiallyl from said axis a distance slightly greater than the opposite end of said surface;

catch means mounted to said bed and having an edge located at a position below said first axis for engagement by said radially inner surface of said hook means, whereby the lower edge of said door is held closely adjacent said bed;

keeper means having parts thereof mounted upon said door and said actuating member adapted to hold said actuating member in a selected position with respect to said door, wherein said hook means is held in a position beneath said catch means when said edge of said door is closely adjacent said bend; and

means coacting with said latch bolt and said actuating member for (1) rotatably urging said hook means into engagement with said catch means when said edge of said door is closely adjacent said bed and said actuating member is maintained in said selected position and (2) rotatably urging said -actuating member away from said selected position when said keeper Ameans is released.

11. A door lock structure according to claim 10, wherein said urging means includes spring means coacting between said latch bolt and -said actuating member for relatively urging said latch bolt and said actuating member in opposite rotational directions, said spring means having one end operably connected to said latch bolt for urging the opposite end of said inner surface of said hook means is positioned beneath said catch means, for maintaining same in contact with said surface when said hook means is positioned beneath sad catch means, the other end of said spring means being operably connected to said actuating member for urging same in an opposite rotational direction away from said selected position, whereby said actuating member is resiliently urged away from said selected position to yassist in unlatching said door when said keeper means is released.

References Cited UNITED STATES PATENTS 820,868 5/ 1906 Hinchliffe 292--200 954,915 4/1910 Bennett 292-200 1,320,175 10/1919 Reid 292-240 2,422,723 6/ 1947 Fisher 292-204 2,741,505 4/1956 Courney 292-341.17 3,347,580 10/1967 Whiting 292-1128 MARVIN A. CHAMPION, Primary Examiner R. L. WOLFE, Assistant Examiner U.S. Cl. X.R. 292-100, 104, 108 

